William gillis



(No Model.)

W. GILLIS. I BANDSAW MILL. No; 384.252. Patented June 12, 1888.

0 u F a w H %7 /47/49//l/I/l///////////////////////////l//l l A m U ITED STATES PATENT OFFICE.

VVILLIAM GILLIS, OF BUCKINGHAM, QUEBEC, CANADA.

BAND-SAW MlLL.

SPECIPICATION forming part of Letters Patent No. 384.252, dated June 12, 1888.

Application filed September 29. 1887. Serial No. ?51,009. (No model.)

.To aZZ whom it may cocern;

Be it known that I, VVILLIAM GILLIS, of Buckingham, in the Province of Quebec, in the Dominion of Canada, have invented certain new and useful Improvenents in 'Band- Saw Mills; and I do hereby declare that the following is a full clear, and exact description of the same, reference being had to the accompanying drawing, which represents in elevation a portion of a band-saw nill provided with my inventon.

My invention has for its object to prevent a band-saw from cracking, to provide for taking up expansion of the saw lengthwise in sawing, to allow expansion and contraction of a bandsaw without liability of being broken, to cause the saw to remain more securely in proper position on the band-saw wheels when in operation, and to insure a more uniforn tension of the saw under all circumstances, and largely do away with the breakage of band-saws, thereby effecting great economy in working bandsaw mills.

My invention consists in hanging the upper wheelin a yielding hearing by a chain and pulleys, one end of the chain attached to aspring and the other end winding on a crab or windlass, so that the spring will cause the chain to keep the saw uniformly st-rained.

Referring to the drawing, A is a hollow column; B, the top wheel journaledin a yoke, C, having a vertical sliding movement in a slot, Q, in the column. The bottom wheel, D,

- is carried by a shaft, E, journaled in a suitable nut, K, hearing on a plate, L, seated on top i of the spring, and a chain connected to the lower end of the bolt, so that the spring will respond immediately to any variable strain ou the chain or saw. The chain then passes under a sheave G on the shaft Fand overa pulley, O, ou the top of the column A, and, if desired, under a second sheave ou the shaft F,and tlen over another pulley at the top of the column, and then over a pulley, P, and then downwardly and around the drum ofa windlass or crab, R, having a ratchet and pawl, L, and a hand-wheel, M, whereby the chain may he tightcned by Operating the windlass to put the required strain on the saw. The drum of the windlass is journaled in the frame of the windlass in movable bearings, above which are springs, N, to allow the chain to have ayielding novement from that end.

I claim as my invention- 1. Aband-sawmill conprising, in combination, an upper and lower sawwheel, the former carried in a yoke and having a pulley on the wheel-shalt, a spring secured to a fixture, a chain attached to said spring and supporting said shaft-pulley, pulleys carrying said chain, and a windlass winding said clain upon a drum journaled on spring-bearings which resist the strain of the chain, whereby all the springs will respond simultaneously to keep the saw at a uniform tension, as set forth.

2. In a bandsaw mi1l,the combinatiomwith the upper saw-wheel journaled inlnovable be'arings and a pulley on said shaft, ofa spring secured to a fixture, a chain attached to said spring and supporting said shalt-pulley, pulleys carrying saidchain, and a windlass winding said chain to adjust the tension of the saw,

as set forth.

WILLIAM GILLIS. VVituesses: I A. H. PARKER, F. WINcHURsT, 

